The Port C I/O Register 0 contains 7 reserved bits, but the descriptor
contains only dummy configuration values for 6 reserved bits, thus
breaking the configuration of all subsequent fields in the register.

Fix this by adding the two missing configuration values.

Fixes: f5e811f2 ("sh-pfc: Add sh7269 pinmux support")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>